I'm an accountant and have used dozens of calculators over my 25 years of bean- counting. The QS2130 is a super light machine to tote around with a full-size key board if you don't need a paper tape. If you learn to use the two memories efficiently for storage you can do without a tape and the twin- power system makes using it anywhere, anytime a breeze. I've owned the previous version QS2125 for almost 18 years and Sharp improved the touch on the QS2130 to make it more comfortable and reliable during input so the QS2125 is now my backup. The QS2130 uses adding-machine logic for keying (not algebraic) so it lets you fly just like the desktop adding machines because of its full size keyboard. There are many controls for sigma, constants, decimal settings and it has a square root key, mark-up, and item count key too plus other features. For the serious number cruncher I can't recommend it enough.